procedures for good zerspanbare lead-free alloys in kupferbasis

摘要

Lead inclusion in copper-containing wrought alloys is coming into disfavor due to health and environmental considerations. Machinability, as well as retention of workability properties, associated with lead inclusion are assured by bismuth together with a modifying element, phosphorus, indium or tin. The modifying element minimizes the workability-precluding embrittlement otherwise caused by bismuth. The alloys are essentially of a stoichiometry and content of prototypical lead-containing alloy as specified as CDA 100-700 series wrought alloys in the 8th edition of the CDA Handbook of Wrought Products except that lead is replaced by bismuth within the weight percent range of 0.5-2 and that such composition invariably contains at least one of the third element additions in the weight percent ranges indicated; 0.1-0.5 P, 0.25-1.0 In, 0.5-6.0 Sn.